We will take a step back and look at a broader picture of Developmental Genetics from the point of view of signaling pathways. A signaling pathway allows cells to communicate with their external envir...We will take a step back and look at a broader picture of Developmental Genetics from the point of view of signaling pathways. A signaling pathway allows cells to communicate with their external environment. In Developmental Biology, this is usually cell-cell interactions. These kinds of interactions are incredibly important because each cell needs to follow its own developmental trajectory in coordination with all the cells around it.